[Commit-gnuradio] r9609 - in gnuradio/trunk/usrp2/fpga: . extram

[matt]

Author: matt
Date: 2008-09-19 17:41:21 -0600 (Fri, 19 Sep 2008)
New Revision: 9609

Added:
   gnuradio/trunk/usrp2/fpga/extram/
   gnuradio/trunk/usrp2/fpga/extram/extram_wb.v
Log:
first cut



Property changes on: gnuradio/trunk/usrp2/fpga/extram
___________________________________________________________________
Name: svn:ignore
   + a.out


Added: gnuradio/trunk/usrp2/fpga/extram/extram_wb.v
===================================================================
--- gnuradio/trunk/usrp2/fpga/extram/extram_wb.v                                
(rev 0)
+++ gnuradio/trunk/usrp2/fpga/extram/extram_wb.v        2008-09-19 23:41:21 UTC 
(rev 9609)
@@ -0,0 +1,146 @@
+
+module extram_wb
+  #(parameter PAGE_SIZE = 10,
+    parameter ADDR_WIDTH = 16)
+    (input clk, input rst,
+     input wb_clk, input wb_rst,
+     input cyc_i, input stb_i,
+     input [ADDR_WIDTH-1:0] adr_i,
+     input we_i,
+     input [31:0] dat_i,
+     output reg [31:0] dat_o,
+     output reg ack_o,
+     
+     inout [17:0] RAM_D,
+     output [PAGE_SIZE-2:0] RAM_A,
+     output RAM_CE1n, output RAM_CENn,
+     output RAM_CLK, output RAM_WEn,
+     output RAM_OEn, output RAM_LDn );
+
+   wire     read_acc = stb_i & cyc_i & ~we_i;
+   wire     write_acc = stb_i & cyc_i & we_i;
+   wire     acc = stb_i & cyc_i;
+
+   assign   RAM_CLK = wb_clk;   // 50 MHz for now, eventually should be 200 MHz
+   assign   RAM_LDn = 0;        // No burst for now
+   assign   RAM_CENn = 0;       // Use CE1n as our main CE
+
+   reg [PAGE_SIZE-2:1] RAM_addr_reg;
+   always @(posedge wb_clk)
+     if(acc)
+       RAM_addr_reg[PAGE_SIZE-2:1] <= adr_i[PAGE_SIZE-1:2];
+   assign             RAM_A[PAGE_SIZE-2:1] = RAM_addr_reg; 
+
+   reg [31:0]         ram_out;
+   always @(posedge wb_clk)
+     if(write_acc)
+       ram_out <= dat_i;
+
+   // RAM access state machine
+   localparam RAM_idle = 0;
+   localparam RAM_read_1 = 1;
+   localparam RAM_read_2 = 2;
+   localparam RAM_read_3 = 3;
+   localparam RAM_read_4 = 4;
+   localparam RAM_write_1 = 6;
+   localparam RAM_write_2 = 7;
+   localparam RAM_write_3 = 8;
+   localparam RAM_write_4 = 9;
+
+   reg               myOE = 0;
+   reg               RAM_OE = 0;
+   reg               RAM_WE = 0;
+   reg               RAM_EN = 0;
+   reg               RAM_A0_reg;
+   reg [3:0]  RAM_state;
+   
+   always @(posedge wb_clk)
+     if(wb_rst)
+       begin
+         RAM_state <= RAM_idle;
+         myOE <= 0; RAM_OE <= 0; RAM_WE <= 0; RAM_EN <= 0; RAM_A0_reg <= 0;
+       end
+     else
+       case(RAM_state)
+        RAM_idle :
+          if(read_acc)
+            begin
+               RAM_state <= RAM_read_1;
+               myOE <= 0; RAM_OE <= 0; RAM_WE <= 0; RAM_EN <= 1; RAM_A0_reg <= 
0;
+            end
+          else if(write_acc)
+            begin
+               RAM_state <= RAM_write_1;
+               myOE <= 0; RAM_OE <= 0; RAM_WE <= 1; RAM_EN <= 1; RAM_A0_reg <= 
0;
+            end
+          else
+            begin
+               myOE <= 0; RAM_OE <= 0; RAM_WE <= 0; RAM_EN <= 0; RAM_A0_reg <= 
0;
+            end
+        RAM_read_1 : 
+          begin
+             RAM_state <= RAM_read_2;
+             myOE <= 0; RAM_OE <= 0; RAM_WE <= 0; RAM_EN <= 1; RAM_A0_reg <= 1;
+          end
+        RAM_read_2 : 
+          begin
+             RAM_state <= RAM_read_3;
+             myOE <= 0; RAM_OE <= 1; RAM_WE <= 0; RAM_EN <= 0; RAM_A0_reg <= 0;
+          end
+        RAM_read_3 : 
+          begin
+             RAM_state <= RAM_read_4;
+             myOE <= 0; RAM_OE <= 1; RAM_WE <= 0; RAM_EN <= 0; RAM_A0_reg <= 0;
+          end
+        RAM_read_4 :
+          begin
+             RAM_state <= RAM_idle;
+             myOE <= 0; RAM_OE <= 0; RAM_WE <= 0; RAM_EN <= 0; RAM_A0_reg <= 0;
+          end
+        RAM_write_1 : 
+          begin
+             RAM_state <= RAM_write_2;
+             myOE <= 0; RAM_OE <= 0; RAM_WE <= 1; RAM_EN <= 1; RAM_A0_reg <= 1;
+          end
+        RAM_write_2 : 
+          begin
+             RAM_state <= RAM_write_3;
+             myOE <= 1; RAM_OE <= 0; RAM_WE <= 0; RAM_EN <= 0; RAM_A0_reg <= 0;
+          end
+        RAM_write_3 : 
+          begin
+             RAM_state <= RAM_write_4;
+             myOE <= 1; RAM_OE <= 0; RAM_WE <= 0; RAM_EN <= 0; RAM_A0_reg <= 0;
+          end
+        RAM_write_4 : 
+          begin
+             RAM_state <= RAM_idle;
+             myOE <= 0; RAM_OE <= 0; RAM_WE <= 0; RAM_EN <= 0; RAM_A0_reg <= 0;
+          end
+        default : RAM_state <= RAM_idle;
+       endcase // case(RAM_state)
+   
+   assign     RAM_A[0] = RAM_A0_reg;
+   assign     RAM_WEn = ~RAM_WE;  // 
((RAM_state==RAM_write_1)||(RAM_state==RAM_write_2));
+   assign     RAM_OEn = ~RAM_OE;
+   assign     RAM_CE1n = ~RAM_EN;    // Active low     (RAM_state != RAM_idle);
+   
+   assign     RAM_D[17:16] = 2'bzz;
+   assign     RAM_D[15:0] = myOE ? 
((RAM_state==RAM_write_3)?ram_out[15:0]:ram_out[31:16]) 
+             : 16'bzzzz_zzzz_zzzz_zzzz;
+
+   always @(posedge wb_clk)
+     if(RAM_state == RAM_read_3)
+       dat_o[15:0] <= RAM_D[15:0];
+     else
+       dat_o[31:16] <= RAM_D[15:0];
+   
+   always @(posedge wb_clk)
+     if(wb_rst)
+       ack_o <= 0;
+     else if((RAM_state == RAM_write_4)||(RAM_state == RAM_read_4))
+       ack_o <= 1;
+     else
+       ack_o <= 0;
+   
+endmodule // extram_wb